Convert function to Simulink block

How do I convert from a开发者_StackOverflow中文版 function, that I have written as an m-file, into a block in a Simulink model?

There's a video here that shows some options. Basically, use the MATLAB Function block. Or, if you want to keep the code separate (and don't care about code generation), you can use the MATLAB Interpreted Function block.